EP2504740B1 - Security module for an automation device - Google Patents

Description

The invention relates to a security module for connection to an automation system or automation device, wherein the automation system is provided for controlling safety-critical and non-safety-critical processes and / or system components according to claim 1. The safety module can be either an input safety module, an output safety module or an input and output safety module. The input / output safety module according to the invention finds particular use in process automation or machine control.

For automation systems for controlling a technical process or a technical system, it is often necessary to control special safety-critical process or system components separately from non-safety-critical components. The modules required for this purpose, such as safety-related controllers and connected safe input / output modules, also referred to as I / O safety modules, are described, for example, in US Pat DE 10 2004061 013 A1 disclosed. The input / output modules described therein have, in addition to control interfaces, additional means for monitoring the redundant field device connection modules integrated in the input / output modules, wherein the field device connection module is connected to the monitoring means by means of one of the control interfaces and the monitoring means communicates with a controller via further control interfaces. The field device connection modules are designed, for example, as standard modules for acquiring process data.

Other safe input / output modules are in the EP 1 703 346 A2 and US 7319406 B2 described. The safety modules operating there as input / output units do not have another non-security communication board for transmitting secure and non-secure data to / from a central processing unit. Thus, in the aforementioned systems, there is no easy way to define a standard interface for safe and non-secure input / output modules.

Also, it often turns out to be difficult to unambiguously separate the safety-critical functions from the non-safety-critical functions.

The previously described safe input / output modules are suitable for use in modular control systems, as described, for example, in US Pat DE 102004056363 A1 are described, not suitable or only with an additional hardware and development effort in an existing modular control system integrated. Another example of the type mentioned is in the DE 103 30916 A1 described.

The invention is accordingly an object of the invention to provide a safe input / output module, which is preferably used in modular automation systems for controlling safety-critical and non-safety-critical processes and / or plant components and avoids the aforementioned disadvantages. In particular, the security module according to the invention, hereinafter also referred to as an input / output security module or I / O security module, should be suitable for equipping an existing modular non-secure control system with an input / output security module in a simple and cost-effective manner.

This object is achieved by an input / output safety module of the type mentioned above with the features specified in claim 1. Advantageous embodiments and improvements of the device according to the invention are specified in further claims and in the description.

The input / output safety module according to the invention is provided for connection to an automation device or automation system, which can be used to control safety-critical and non-safety-critical processes and / or system components.

The input / output safety module comprises a communication board whose processing unit can be connected to a central unit (CL) via an I / O bus slave and an external input / output bus connected to it not safety-critical process and / or non-safety-critical plant components is provided, as well as for safety-critical processes and / or safety-critical plant components.

According to the invention an internal, preferably designed as a serial interface communication master is provided on the communication board, which is connected via at least one connectable first communication link and with secure processing units one or more boards with safety-related input / output circuits for safety-related functions, that at least one safety-related printed circuit board can exchange telegrams with the communication board.

Furthermore, field devices for safety-critical processes and / or plant components can be connected to the safety-related input / output circuits via a corresponding interface.

A synchronization connection is provided between the secure processing units for synchronization or for data synchronization with one another, as a result of which the secure processing units mutually monitor and synchronize.

For example, the monitoring and synchronization mechanisms may be " PROFIsafe - Profile for Safety Technology on PROFIBUS DP and PROFINET IO Profile part, related to IEC 61784-3-3 Specification for PROFIBUS and PROFINET. Version 2.4, March, 2007, Order No: 3.192b or similar

Furthermore, the invention provides that safety-oriented telegrams to the processing unit of the communication board's means of at least one of the security processors located on the boards for the safety-related functions and the corresponding internal communication slave a second internal communication connection via the internal communication master are transferable. This ensures that only one of the safety processors sends the safety-related telegrams to the internal communication master of the communication board.

In one embodiment of the input / output security module according to the invention, the second internal communication connection is designed such that the telegrams sent by the communication board can also be received via it.

In an advantageous manner, the communication board carries out the safety-related communication via the external input / output bus master arranged on the central unit using a so-called black channel communication principle to the internal serial communication slaves of the printed circuit boards for the safety-related functions, hereinafter also referred to as Safety Control boards marked, from.

For safety-related communication with the Safety Control Board, the communication board undertakes the task of forwarding the safety-related telegrams to an external input / output bus master arranged on a central unit by means of an integrated safety layer.

For this purpose, the so-called "black channel communication principle" is used, which enables a secure transmission of safety-related protocols and, for example, " PROFIsafe - Profile for Safety Technology on PROFIBUS DP and PROFINET IO Profile part, related to IEC 61784-3-3 Specification for PROFIBUS and PROFINET. Version 2.4, March, 2007, Order No: 3.192b "is known.

Due to the separation in communication board and safety modules is achieved in an advantageous manner that the safety-related parts in input / output safety modules are strictly separated from the non-safety-critical communication. This significantly reduces the development effort of new EIA security modules and the safety-critical functions of the non-safety-critical functions can be separated more strictly.

In another advantageous embodiment, it is provided to construct an I / O safety module such that existing Safety Control Board's are upgraded with the communication board described above and only the internal communication connections between the Safety Control Board's and the communication board are added ,

In a preferred embodiment, the I / O security module has a redundant internal 1002 (1 of 2) security architecture consisting of two security processors with corresponding units for communicating with each other. In order to enable fast synchronization and / or monitoring between the security processors, the units for data exchange are preferably designed as dual port RAM. The dual-port RAMs are designed so that simultaneous read and / or write accesses are possible at its two access sides, so that a simultaneous access for two otherwise separate systems is possible, working with shared data without the otherwise separate systems each other restrict access speed. This significantly increases the access time to the safety-related telegrams to be transmitted.

However, the I / O security module may also be constructed in a security structure different from the 1002 (1 of 2) architecture, such as a 1003 architecture, etc. In the described 1002 architecture, the security processor, which can communicate directly with the communications board, is unable to detect a Cyclic Redundancy Checksum (CRC) - a method for determining a data check value to detect transmission or storage errors to determine) that is necessary to generate valid secure telegrams over an internal communication connection. This CRC determination can only be performed by the redundant processor and communicated to the first processor. This ensures that both processors participate in valid telegrams. This is necessary to ensure the safety of the system in case of failure or malfunction of one of the two processors of the Safety Controller.

The input / output safety module with the, preferably two, redundant processing units for the safety-critical input and output circuits can be flexible according to the design of the safety-related input / output circuits on the Safety Control Board's as safe analog and / or digital I / O circuits be used for different functions, for example, for connection to analog and / or digital inputs and outputs of the field devices.

The input / output safety module can also be used in larger automation systems as a decentralized input and / or output device in such a decentralized, larger automation system, or in stand-alone automation devices as a locally connectable input / output device.

Another advantage of the security module according to the invention results from the fact that a, preferably modular, control system for non-safety-critical applications can be upgraded in a simple and cost-effective manner without extensive hardware expenditure for safety-critical applications.

Reference to the embodiments illustrated in the following figures, the invention and advantageous refinements and improvements of the invention will be explained and described in detail.

Fig. 1

eine beispielhafte Ausführungsform eines modular aufgebauten Steuerungssystems für die Steuerung sicherheitsgerichteter und nichtsicherheitsgerichteter Prozesse mit den erfindungsgemäßen Sicherheitsmodulen,

Fig. 2

eine detaillierte Ausführungsform des erfindungsgemäßen Sicherheitsmoduls in einer 1002 Architektur und die Kommunikation innerhalb des Sicherheitsmoduls und über den externen Ein-/Ausgabebus zur Zentraleinheit und/oder über die Buskoppler zu weiteren dezentralen Einheiten, und

Fig. 3

eine beispielhafte Hardwarestruktur des Sicherheitsmoduls basierend auf einer 1002 Sicherheitsstruktur.

Show it:

Fig. 1

an exemplary embodiment of a modular control system for the control of safety-related and non-safety-oriented processes with the safety modules according to the invention,

Fig. 2

a detailed embodiment of the security module according to the invention in a 1002 architecture and communication within the security module and via the external input / output bus to the central unit and / or via the bus coupler to other decentralized units, and

Fig. 3

an exemplary hardware structure of the security module based on a 1002 security structure.

Fig. 1 shows a modular control or automation system with a first control unit 1, which is provided for the control of non-safety-critical processes and / or non-safety critical system components, with attached modules of the central input / output units 11, 21, via a preferably designed as a backplane bus so-called external input / output bus IOB1 and an integrated in the first control unit input / output bus master 1a are each connected to the first control unit 1, and optionally with at least one designed as a field bus master coupler communication coupler module 5, 6th which controls the communication via the fieldbus FB with a plurality of fieldbus slaves 7, 8 and input / output units 71, 72, 81, 82 connected thereto.

For example, the bus master couplers 5, 6 are each connected to the first control unit 1 via an internal coupler bus, which is constructed similarly to the communication coupler 5, 6.

Furthermore, at least one second control unit 2, also referred to below as a safety controller, is provided for the control of safety-critical and / or safety-critical system components. To provide the safety-related functions, the safety controller 2 comprises at least two processors and a first interface, preferably designed as a dual-port RAM, wherein only one of the two processors is connected to the dual-port RAM. The safety controller 2 communicates with the first control unit 1 via the dual-port RAM.

The input / output units comprise both safe units 21, 72, 82 with safety function and non-safe units 11, 71, 81 without safety function.

The first control unit 1 forms with the safety controller 2, a power supply unit and a display and / or operating unit a module for the central unit CL of a control or automation system.

Both the module directly connected to the module for the central unit CL of the so-called central input / output units 11, 21 and the modules of the decentralized units 71, 72, 81, 82, as already stated, according to their function both as safety-oriented as also not safety-related devices be executed.

The in the Fig. 1 Decentralized units 71, 72, 81, 82 are likewise connected to one another via a further input / output bus IOB2, IOB3, which is preferably designed as a backplane bus, the respective input / output bus IOB2, IOB3 being connected via a fieldbus slave 7, 8 integrated input / output bus master 1 b, 1 c are connected to the fieldbus.

In the input / output units 11, 21, 71, 72, 81, 82 preferably three printed circuit boards LP1, LPS1, LPS2 are integrated, which exchange data with each other via at least one internal communication link IKB, IKB1, IKB2. In this case, only data is sent to the Safety Control Board's via the first communication link IKB1. Data can be sent to and from the Safety Control Board via the second communication link IKB2. For this purpose, at least one internal communication slave is provided on safety control boards, which can be connected to the internal communication connections. The communication link IKB is used only in non-safety-related input / output units 11, 71, 81 for non-safety-related data transmission.

The electrical and / or mechanical design of the input / output devices, for example, in the DE 10 2008 058 090 described structure of the input / output modules correspond.

Based on a preferred 1002 architecture of the FIG. 1 In the control system shown, the safe units 21, 72, 82 comprise, in addition to the first circuit board LP1 for the non-safety-related communication, two further circuit boards LPS1, LPS2 for the safety-critical or safety-related functions. The communication between the further printed circuit boards LPS1, LPS2 takes place by means of a synchronization connection IF2. These are on the other circuit boards LPS1, LPS2 at least two, designed as security processors, processing units provided with associated memories and clocks. The security processors synchronize with each other. The structure of the security processors and their operation are known from the relevant prior art.

The central unit CL, like the input / output units 11, 21 and the communication couplers 5, 6, can be arranged on a differently expandable base plate by means of a module carrier, the input / output units 11, 21 directly to the central unit CL and the communication coupler 5, 6 can be coupled. The baseplate also has a field bus connection for a standard fieldbus connection to the decentralized units 7, 8 and / or decentralized stations.

In a particular embodiment, the base plate is snapped onto a DIN standard rail, wherein at least one of the input / output units 11, 21 can also be snapped onto the DIN rail and can be plugged together electrically and mechanically with the respective base plate.

It also proves advantageous that modules of the central unit CL, the input / output units 11, 21 and the communication coupler 5, 6 are all electrically connected or connected to one another wirelessly via plug-in connections. Preferably, the central unit CL, the input / output units 11, 21 and the communication coupler 5, 6 are each detachably connected or connected to each other by means of plug and / or locking means.

Fig. 2 shows a detailed embodiment of the inventive I / O safety module in a 1002 architecture with two redundant Safety Control Board's LPS1, LPS2 and the communication within the security module and via the input / output bus IOB1 and the connectable I / O bus module. Master 1.

The input / output safety module comprises a first printed circuit board LP1 designed as a communication board for providing the non-safety-critical communication via an input / output bus slave 12 and the input / output bus IOB1, which is preferably connected as a backplane bus , with an internal communication master 10 and a connectable thereto, preferably designed as a serial interface, internal communication link IKB1, IKB2.

The input / output bus IOB1 is provided for the inventive I / O security module with the central unit CL as shown in FIG Fig. 1 via the integrated in the central unit input / output bus master to connect 1a.

Via the internal communication connection IKB1, IKB2, the communication board LP1 is connected to two printed circuit boards LPS1, LPS2 with safety-related input / output circuits for safety-related functions, which are also referred to as safety control boards. Safety-related functions of the Safety Control Board are, for example, self-monitoring measures in the input / output safety module, such as comparison tests between the channels, self-tests, paus- ability tests but also monitoring for power failure, short circuit, overvoltage or overrange.

On the Safety Control Board's LPS1, LPS2, a safety-related application 25, 35 is executed, which is used to process safe signals in safe input / output units.

For the data exchange or the synchronization, a synchronization connection IF2 is provided between the Safety Control Board's LPS1, LPS2.

Fig. 3 shows an exemplary hardware structure of the security module according to the invention based on a 1002 security structure.

The exemplary hardware structure of the security module shown here is based on a 1002 security structure with the first processing unit 14 arranged on the communication board LP1 and in each case on the safety control Board's LPS1, LPS2 arranged safety processors 24, 34, hereinafter referred to as the first safety processor 24, arranged on the first safety control board LPS1, and as a second safety processor 34, arranged on the second safety control board LPS2, are referred to.

The executed as security processors processing units 24, 34 are each assigned corresponding memory and clock. The security processors 24, 34 are designed to monitor each other. For this purpose, the processors 24, 35 synchronize with each other via the synchronization connection IF2.

One of the two security processors 24, 34, in the example shown, the first safety processor 24 of the first safety control board LPS1, is connected to the communication board LP1 via a separate internal communication channel, also referred to as second internal communication link IKB2, in such a way that the communication Board LP1 can exchange the safety-related telegrams with the Safety Control Board's LPS1.

For voltage monitoring, for example, to overvoltage or power failure, a monitoring unit 40 is provided, which is preferably arranged on the communication board and each with the arranged on the Safety Control Board's LPS1, LPS2 input / output circuits 23, 33 via the connections K1, K2 is connected to enable voltage monitoring in the input / output safety module.

As a result of the redundant arrangement of the security processors 24, 34, in the present exemplary embodiment only the first security processor 24 of the first safety control board LPS1 is designed to transmit safety-related telegrams to the processing unit 14 of the communication board LP1 via the internal second communication link IKB2.

In the described 1002 architecture, the security processor 24, which is capable of exchanging telegrams directly with the communication board LP1, is unable to perform a Cyclic Redundancy Checksum (CRC) Check value for data in order to be able to detect errors during transmission or storage), which is necessary for generating valid secure telegrams over an internal communication connection. This CRC calculation can only be performed by the redundant processor 34 and communicated to the first processor 24 via internal connection IF2. This ensures that both processors participate in valid telegrams. This is necessary to ensure the safety of the system in case of failure or malfunction of one of the two processors of the Safety Controller.

Field devices for safety-critical processes and / or plant components, also referred to as safety-related field devices, can be connected to safety control boards LPS1, LPS2 by means of the mutually monitoring safe input / output circuits 23, 33 via an interface 50 and via the input / output bus. Slave 12 and the connected external input and output bus IOB1, for example, the central unit (CL) can be connected.

Secure input and / or output channels with interface 50 are redundantly distributed on both secure circuit boards LPS1, LPS2 and processed by secure processing units 24, 34 by means of secure circuits 23, 33.

Claims (9)

1. Safety module for connection to an automation device or automation system, wherein the automation device or automation system is provided for the control of safety-critical and non-safety-critical processes and/or plant components, comprising a communication board (LP1) for providing non-safety-critical communication, the processing unit (14) of which can be connected (CL) via an input/output bus slave (12) and an external input/output bus (IOB1) connected thereto to a central processing unit, characterized in that

   - the safety module, in addition to the communication board (LP1) for providing the non-safety-critical communication, comprises one or more circuit boards (LSP1, LSP2) also having safety-oriented input/output circuits (23), (33) for safety oriented functions,

   - the communication board (LP1) has a serial communication master (10) which is connected via at least one communication link (IKB1) connectable thereto to one or more secure processing units (24), (34) arranged on one or more of the circuit boards (LPS1, LPS2) having safety-oriented input/output circuits (23), (33) for safety-oriented functions, in such a manner that at least one of the circuit boards (LPS1, LPS2) is provided for receiving the messages sent by the communication board,

   - on the circuit boards (LPS1, LPS2) for the safety-oriented functions in each case at least one internal communication slave (20), (30) is provided which can be connected to the serial communication master (10) via the internal communication link (IKB1),

   - further field devices for safety-critical processes and/or plant components can be connected to the safety-oriented input/output circuits (23, 33) via an interface (50),

   - the synchronization between the secure processing units (24), (34) can be carried out by means of a synchronization link (IF2), and

   - safety-oriented messages can be transmitted from and/or to the processing unit (14) of the communication board (LP1) by means of at least one second internal communication link (IKB2) only via one of the secure processing units (24) located on the circuit boards (LPS1, LPS2) for the safety-oriented functions.
2. Safety module according to Claim 1, characterized in that the secure processing units (24, 34) are in each case connected to the serial communication master (10) of the communication board (LP1) via an internal communication slave (20, 30) and the internal communication links (IKB1, IKB2).
3. Safety module according to Claim 1 or 2, characterized in that the safety module can be connected via the input/output bus (IOB) to an input/output bus master (1a) of a control unit which is provided for the control of the non-safety-critical process and/or of the non-safety-critical plant components and also for safety-critical and/or safety-critical plant components.
4. Safety module according to Claim 3, characterized in that safety-oriented messages can be transmitted from and to the circuit boards (LPS1, LPS2) by utilizing the black channel communication principle via the external input/output busmaster (1a) and the internal serial communication slave (20, 30) of the circuit boards (LPS1, LPS2) also for the safety-oriented functions.
5. Safety module according to one of the preceding claims, characterized in that the second internal communication link (IKB2) is constructed in such a manner that the messages sent by the communication board (LP1) can also be received via it.
6. Safety module according to one of the preceding claims, characterized in that the mutual synchronization and/or monitoring of the secure processing units (24), (34) can be carried out via at least one synchronization link (IF2).
7. Safety module according to one of the preceding claims, characterized in that of the secure processing units (24), (34), only one processing unit sends safety-oriented messages directly to the communication master (10) of the communication board (LP1) via the second internal communication link (IKB2).
8. Safety module according to one of the preceding claims, characterized in that it can be used in a modularly constructed control system.
9. Use for the safety module according to one of the preceding claims in automation devices or automation systems of process automation or machine control as a central or decentralized input and/or output device.

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